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Abstract:

A slider for a head gimbal assembly includes a trailing surface, a
plurality of connection pads arranged on the trailing surface adapted for
both bonding the slider to a suspension of the head gimbal assembly and
testing the performance of the slider. At least a part of the connection
pads each comprises a bonding portion and a testing portion electrically
connected to the bonding portion and larger than the bonding portion, all
the bonding portions and the rest part of the connection pads are
arranged in a first row and the testing portions are arranged outside the
first row. The slier of the present invention has a new pad layout to
facilitate bonding of the connection pads and permit to provide
additional pads thereon to connect the additional sensors therein for
precise reading and writing, thereby improving the performance of the
slider. The invention also discloses a head gimbal assembly and a disk
drive unit including the same.

Claims:

1. A slider for a head gimbal assembly, comprising: a trailing surface; a
plurality of connection pads arranged on the trailing surface adapted for
both bonding the slider to a suspension of the head gimbal assembly and
testing the performance of the slider; wherein at least a part of the
connection pads each comprises a bonding portion and a testing portion
electrically connected to the bonding portion and larger than the bonding
portion, all the bonding portions and the rest part of the connection
pads are arranged in a first row, and the testing portions are arranged
outside the first row.

2. The slider as claimed in claim 1, wherein the rest part of the
connection pads each has the same dimension as the testing portion.

3. The slider as claimed in claim 1, wherein the bonding portions and the
rest part of the connection pads are arranged alternately.

4. The slider as claimed in claim 1, wherein the testing portions are
arranged in a second row.

5. The slider as claimed in claim 1, wherein the testing portions are
arranged in a plurality of rows.

6. The slider as claimed in claim 1, wherein the bonding portions, the
testing portions, and the rest part of the connection pads have the same
layer structure.

7. The slider as claimed in claim 6, wherein the layer structure
comprises a copper stud, a titanium or tantalum layer, a nickel-iron
alloy layer and a gold layer.

8. A head gimbal assembly, comprising: a suspension having a suspension
tongue with a plurality of electrical pads; and a slider mounted on the
suspension tongue, comprising: a trailing surface; a plurality of
connection pads arranged on the trailing surface adapted for both bonding
the slider to the suspension and testing the performance of the slider;
wherein at least a part of the connection pads each comprises a bonding
portion and a testing portion electrically connected to the bonding
portion and larger than the bonding portion, all the bonding portions and
the rest part of the connection pads are arranged in a first row, and the
testing portions are arranged outside the first row.

9. The head gimbal assembly as claimed in claim 8, wherein the rest part
of the connection pads each has the same dimension as the testing
portion.

10. The head gimbal assembly as claimed in claim 8, wherein the bonding
portions and the rest part of the connection pads are arranged
alternately.

11. The head gimbal assembly as claimed in claim 8, wherein the testing
portions are arranged in a second row.

12. The head gimbal assembly as claimed in claim 8, wherein the testing
portions are arranged in a plurality of rows.

13. The head gimbal assembly as claimed in claim 8, wherein the bonding
portions, the testing portions, and the rest part of the connection pads
have the same layer structure.

14. The head gimbal assembly as claimed in claim 13, wherein the layer
structure comprises a copper stud, a titanium or tantalum layer, a
nickel-iron alloy layer and a gold layer.

15. A disk drive unit, comprising: a head gimbal assembly including a
suspension having a suspension tongue with a plurality of connection pads
and a slider mounted on the suspension tongue; a drive arm connected to
the head gimbal assembly; a disk; and a spindle motor operable to spin
the disk; wherein the slider comprising: a trailing surface; a plurality
of connection pads arranged on the trailing surface adapted for both
bonding the slider to the suspension and testing the performance of the
slider; wherein at least a part of the connection pads each comprises a
bonding portion and a testing portion electrically connected to the
bonding portion and larger than the bonding portion, all the bonding
portions and the rest part of the connection pads are arranged in a first
row, and the testing portions are arranged outside the first row.

16. The disk drive unit as claimed in claim 15, wherein the rest part of
the connection pads each has the same dimension as the testing portion.

17. The disk drive unit as claimed in claim 15, wherein the bonding
portions and the rest part of the connection pads are arranged
alternately.

18. The disk drive unit as claimed in claim 15, wherein the testing
portions are arranged in a second row.

19. The disk drive unit as claimed in claim 15, wherein the testing
portions are arranged in a plurality of rows.

20. The disk drive unit as claimed in claim 15, wherein the bonding
portions, the testing portions, and the rest part of the connection pads
have the same layer structure.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to magnetic hard disk drive device
and, more particularly, to a slider with a new pad layout, head gimbal
assembly and disk drive unit with the same.

BACKGROUND OF THE INVENTION

[0002] One known type of information storage device is a disk drive device
that uses magnetic media to store data and a movable read/write head that
is positioned over the magnetic media to selectively read from or write
to the magnetic media.

[0003] FIG. 1 illustrates a conventional disk drive device and show a
magnetic disk 101 mounted on a spindle motor 102 for spinning the disk
101. A voice coil motor arm 104 carries a head gimbal assembly (HGA) 100
that includes a slider 110 incorporating a read/write head. A voice-coil
motor (VCM, not labeled) is provided for controlling the motion of the
motor arm 104 and, in turn, controlling the slider 110 to move from track
to track across the surface of the disk 101, thereby enabling the
read/write head to read data from or write data to the disk 101. In
operation, a lift force is generated by the aerodynamic interaction
between the slider 110, incorporating the read/write head, and the
spinning magnetic disk 101. The lift force is opposed by equal and
opposite spring force which is applied by the HGA 100 such that a
predetermined flying height above the surface of the spinning disk 101 is
maintained over a full radial stroke of the motor arm 104.

[0004] Now referring to FIG. 2a and FIG. 2b, the conventional HGA 100
includes a slider 110 having a reading/writing head imbedded therein, a
suspension 120 to load or suspend the slider 110 thereon. As illustrated,
the suspension 120 includes a load beam 130, a base plate 140, a hinge
150 and a flexure 160, all of which are assembled together.

[0005] As illustrated in FIG. 3a and FIG. 3b, pluralities of electrical
traces 161 are formed on the flexure 160 along length direction thereof.
One end of the electrical traces 161 are electrically connected to six
electrical pads 162 which are formed on the suspension tongue 163, and
the other end of the electrical traces 161 are electrically connected to
an outer control system (not shown). A trailing surface 111 of the slider
110 has six connection pads 112 corresponding to the six electrical pads
162. Concretely, the connection pads 112 are electrically connected to
the electrical pads 162 by solder joints 164, thus connected to the
electrical traces 161, thereby electrically connecting the slider 110 to
the electrical traces 161. After the slider 110 mounted on the suspension
tongue 163 and electrically coupled with the electrical pads 162 by the
connection pads 112, the outer control system can control the slider 110,
thus realizing data reading/writing operation with respect to the disks
101.

[0006] As indicated above, the number of the connection pads 112 formed on
the trailing surface 111 of the slider 110 is six. The connection pads
112 are arranged to be one row and adjacent to a mounting surface which
face to the suspension tongue 163 for bonding with the electrical pads
162 disposed on the suspension tongue 163 and testing the performance of
the slider before bonding. And all of the connection pads 112 are used to
electrically connect the inner sensors of the slider 110 to an outer
control system (not shown) by the electrical traces 161. Concretely,
there are three inner sensors embedded into the slider 110. Every two
connection pads 112 are connected to one inner sensor. Wherein one pair
of the connection pads 112 are electrically connected to a read head (not
shown) adapted for reading data from the disk, another pair of pads 112
are electrically connected to a write head (not shown) adapted for
writing data to the disk, and the other two connection pads 112 are
electrically connected to a thermal resistance to heat the pole tip
formed on an air bearing surface 113 of the slider 110 which facing to
the disk 101 and then make the pole tip extrude, thereby improving the
precision of reading and writing of the slider 110.

[0007] However, on one hand, the slider is required to become more and
more smaller. This, in turn will result in smaller space between the
connection pads. While bonding the connection pads to the electrical pads
of the suspension tongue, the precision control is required to prevent
short circuit. That is to say, it becomes difficult to bond the smaller
slider to the suspension.

[0008] On the other hand, consumers are constantly desiring greater
storage capacity for such disk drive devices, as well as faster and more
accurate reading and writing operations. Thus, disk drive manufacturers
have continued to develop higher capacity disk drives by, for example,
increasing the density of the information tracks on the disks by using a
narrower track width and/or a narrower track pitch. However, each
increase in track density requires that the disk drive device has a
corresponding increase in the positional control of the read/write head
in order to enable quick and accurate reading and writing operations
using the higher density disks. As the track density increases, it
becomes more and more difficult using known technology to quickly and
accurately position the read/write head over the desired information
tracks on the storage media. Thus, disk drive manufacturers are
constantly seeking ways to improve the positional control of the
read/write head in order to take advantage of the continual increase in
track density.

[0009] One approach that has been effectively used by disk drive
manufacturers to improve the positional control of read/write heads for
higher density disks is to adopt a series of sensors, such as vibration
sensor, head disc interface sensor (HDI sensor) and so on. If the
additional sensors are set outside the slider, the electrical signal of
the sensors will be delayed inevitably as a result the slier can not be
adjusted in time. Thus it requests all the increased sensors to be set
inside the slider to improve the performance of the slider.

[0010] However, more sensors are embedded into the slider, more connection
pads need to be disposed on the slider. But the slider is limited to 700
μm in width at present, and it requests to keep enough space between
each two connection pads to prevent short circuit. Furthermore, in order
to meet the request of bonding, the connection pads must be arranged to
be one row, and in order to meet the request of testing, the dimension of
each connection pad is limited to 60 μm×60 μm at least.
Therefore, conventional layout of the connection pads makes the slider
difficult to provide additional pads thereon.

[0011] Accordingly, it is desired to provide a slider with a new pad
layout to facilitate bonding of the connection pads and permit to provide
additional pads thereon to connect the additional sensors therein for
precise reading and writing to overcome the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

[0012] One objective of the present invention is to provide a slider with
a new pad layout to facilitate bonding of the connection pads and permit
to provide additional pads thereon to connect the additional sensors
therein for precise reading and writing, thereby improving the
performance of the slider.

[0013] Another objective of the present invention is to provide a HGA
including a slider with a new pad layout to facilitate bonding of the
connection pads and permit to provide additional pads thereon to connect
the additional sensors therein for precise reading and writing, thereby
improve the performance of the slider.

[0014] Yet another objective of the present invention is to provide a disk
drive unit including a slider with a new pad layout to facilitate bonding
of the connection pads and permit to provide additional pads thereon to
connect the additional sensors therein for precise reading and writing,
thereby improving the performance of the slider to meet the performance
necessary of the disk drive unit.

[0015] To achieve above objectives, a slider for a head gimbal assembly
includes a trailing surface, a plurality of connection pads arranged on
the trailing surface adapted for both bonding the slider to a suspension
of the head gimbal assembly and testing the performance of the slider. At
least a part of the connection pads each includes a bonding portion and a
testing portion electrically connected to the bonding portion and larger
than the bonding portion, all the bonding portions and the rest part of
the connection pads are arranged in a first row and the testing portions
are arranged outside the first row.

[0016] As an embodiment of the present invention, the rest part of the
connection pads each has the same dimension as the testing portion.

[0017] As another embodiment of the present invention, the bonding
portions and the rest part of the connection pads are arranged
alternately. Preferably, the testing portions are arranged in a second
row.

[0018] As still another embodiment of the present invention, the testing
portions are arranged in a plurality of rows.

[0019] As yet another embodiment of the present invention, the bonding
portions, the testing portions, and the rest part of the connection pads
have the same layer structure. Preferably, the layer structure includes a
copper stud, a titanium or tantalum layer, a nickel-iron alloy layer and
a gold layer.

[0020] A head gimbal assembly of the present invention includes a
suspension having a suspension tongue with a plurality of electrical pads
and a slider mounted on the suspension tongue, which includes a trailing
surface, a plurality of connection pads arranged on the trailing surface
adapted for both bonding the slider to a suspension of the head gimbal
assembly and testing the performance of the slider. At least a part of
the connection pads each includes a bonding portion and a testing portion
electrically connected to the bonding portion and larger than the bonding
portion, all the bonding portions and the rest part of the connection
pads are arranged in a first row and the testing portions are arranged
outside the first row.

[0021] A disk drive unit of the present invention includes include a head
gimbal assembly including a suspension having a suspension tongue with a
plurality of electrical pads and a slider mounted on the suspension
tongue, a drive arm connected to the head gimbal assembly, a disk and a
spindle motor operable to spin the disk. The slider includes a trailing
surface, a plurality of connection pads arranged on the trailing surface
adapted for both bonding the slider to a suspension of the head gimbal
assembly and testing the performance of the slider. At least a part of
the connection pads each includes a bonding portion and a testing portion
electrically connected to the bonding portion and larger than the bonding
portion, all the bonding portions and the rest part of the connection
pads are arranged in a first row and the testing portions are arranged
outside the first row.

[0022] In comparison with the prior art, the slider of the present
invention includes a plurality of connection pads, each of which includes
a bonding portion and a testing portion. The bonding portions and the
testing portions are not arranged in a same row. Since the bonding
portion is provided just for bonding, it can be designed to be a smaller
size that just enough for bonding. Therefore, on one hand, the space
between the bonding portions can be enlarged to facilitate the bonding;
on the other hand, the trailing surface of the slider can be placed more
connection pads thereon, thereby improve the performance of the slider.

[0023] Other aspects, features, and advantages of this invention will
become apparent from the following detailed description when taken in
conjunction with the accompanying drawings, which are a part of this
disclosure and which illustrate, by way of example, principles of this
invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings facilitate an understanding of the
various embodiments of this invention. In such drawings:

[0034]FIG. 7 is a perspective view of a slider of the HGA shown in FIG.
5;

[0035]FIG. 8 is a perspective view of a slider according to a second
embodiment of the present invention;

[0036]FIG. 9 is a perspective view of a slider according to a third
embodiment of the present invention;

[0037]FIG. 10 is a perspective view of a disk drive unit according to an
embodiment of the invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0038] Various preferred embodiments of the invention will now be
described with reference to the figures, wherein like reference numerals
designate similar parts throughout the various views. As indicated above,
the invention is directed to a slider for a HGA of a disk drive unit,
which includes a trailing surface, a plurality of connection pads
arranged on the trailing surface adapted for both bonding the slider to a
suspension of the head gimbal assembly and testing the performance of the
slider. At least a part of the connection pads each includes a bonding
portion and a testing portion electrically connected to the bonding
portion and larger than the bonding portion, all the bonding portions and
the rest part of the connection pads are arranged in a first row and the
testing portions are arranged outside the first row. The slider of the
present invention includes a plurality of connection pads, each of which
includes a bonding portion and a testing portion. The bonding portions
and the testing portions are not arranged in a same row. Since the
bonding portion is provided just for bonding, it can be designed to be a
smaller size that just enough for bonding. Therefore, on one hand, the
space between the bonding portions can be enlarged to facilitate the
bonding; on the other hand, the trailing surface of the slider can be
placed more connection pads thereon, thereby improving the performance of
the slider. Several example embodiments of the slider, a head gimbal
assembly (HGA) with such a slider of the invention will now be described.

[0039]FIG. 4a-4b show a detail structure of an embodiment of a HGA of the
present invention. Now referring to FIG. 4a and FIG. 4b, a HGA 200 of the
present invention includes a slider 210 and a suspension 220 supporting
the slider 210. The suspension 220 includes a load beam 230, a base plate
240, a hinge 250, a flexure 260, and, all of which are assembled with
each other.

[0040] The load beam 230 is connected to the base plate 240 by the hinge
250. A locating hole 231 is formed on the load beam 230 for aligning the
load beam 230 with the flexure 260. As best shown in FIG. 4b, a dimple
232 is formed on the load beam 230 to transfer the load forces generated
by the load beam 230 to the flexure 260 at a position corresponding to a
center of the slider 210. By this engagement of the dimple 232 with the
flexure 260, the load forces can be transferred to the slider 210
uniformly, thus making the slider 210 working more stably.

[0041] The base plate 240 is used to enhance the structure stiffness of
the whole HGA 200. A mounting hole 241 is formed on end of the base plate
240 for mounting the whole HGA 200 to a motor arm (not shown). The hinge
250 has a mounting hole 251 formed on its one end corresponding to the
mounting hole 241 of the base plate 240, and the hinge 250 is partially
mounted to the base plate 240 with the mounting holes 241, 251 aligned
with each other. The hinge 250 and the base plate 240 may be mounted
together by laser welding. Two hinge steps 252 are integrally formed at
two sides of the hinge 250 at one end adjacent to the mounting hole 251
for strengthening the stiffness of the hinge 250. In addition, two hinge
struts 253 are extended from the other end of the hinge 250 to partially
mount the hinge 250 to the load beam 230. In this embodiment, the hinge
250 is integrally formed with the base load beam 230.

[0042] The flexure 260 runs from the hinge 250 to the load beam 230. The
flexure 260 has a proximal end 268 adjacent to the hinge 250 and a distal
end 269 adjacent to the load beam 230. The flexure 260 of the suspension
220 has a suspension tongue 263 on which almost an entire surface of one
face of the slider 210 is fixed. A locating hole 267 is formed on the
distal end 269 of the flexure 260 and aligned with the locating hole 231
of the load beam 230, thus obtaining a high assembly precision.

[0043] FIG. 5 is a perspective view of the HGA shown in FIG. 4a. Referring
to FIG. 5, a plurality of electrical traces 261 is formed on the flexure
260. One end of the electrical traces 261 are electrically connected to
ten electrical pads 262 which are formed on the suspension tongue 263 and
another end of the electrical traces 261 are electrically connected to an
outer control system (not shown).

[0044] Now referring to FIG. 6 and FIG. 7, the slider 210 mounted on the
suspension tongue 263 includes a trailing surface 211, a mounting surface
and an air bearing surface 212 opposite to the mounting surface. The
mounting surface is bonded to the suspension tongue 263 by epoxy or other
adhesive materials. The slider 210 further includes a plurality of
connection pads arranged on the trailing surface 211. A part of the
connection pads are first connection pads 213, and the rest part of the
connection pads are second connection pads 214. Each first connection
pads 213 includes a bonding portion 213a for bonding and a testing
portion 213b electrically connected to the bonding portion 213a for
testing. All the bonding portions 213a and the second connection pads 214
are arranged in a first row adjacent to the mounting surface of the
slider 210 for bonding with the electrical pads 262 of the suspension
tongue 263 by solder joints 264 so as to electrically connect the inner
sensor of the slider to the outer control system (not shown). Preferably,
the bonding portions 213a and the second connection pads 214 are arranged
alternately. While the testing portions 213b are arranged outside the
first row. Preferably, the testing portions 213b are arranged in a second
row adjacent to the air bearing surface 212 of the slider 210 in order to
facilitate the testing of the first connection pads 213. The second
connection pad 214 have the same dimension as the testing portion 213b
for both bonding and testing. Thus, each combination of the bonding
portion 213a and the testing portion 213b has the same function as each
second connection pad 214.

[0045] Since the bonding portion 213a is disposed just for bonding, it
does not need to be designed as big as the testing portion 213b. Thus,
the bonding portion 213a can be designed to be a smaller size that just
enough for bonding. Therefore, on one hand, the space between the bonding
portion 213a and the second connection pad 214 can be enlarged to
facilitate the bonding. On the other hand, the trailing surface can be
placed more connection pads thereon. In this embodiment, the width of the
bonding portion 213a is half as that of the testing portion 213b. There
are five first connection pads 213 and five second connection pads 214
disposed on the trailing surface 211 of the slider 210. The total number
of the connection pads is ten, so the number of the inner sensors
imbedded in the slider 210 can be five. Except the read head, write head
and thermal resistance, two additional sensors, such as a vibration
sensor and a head disc interface sensor, can be imbedded in the slider
210 to adjust the flying height of the slider 210, thereby improving the
precision of reading and writing of the slider 210.

[0046] Concretely, the bonding portion 213a, testing portion 213b and the
second connection pad 214 have the same layer structure. Preferably, the
layer structure include a copper stud, a titanium or tantalum layer, a
nickel-iron alloy layer and a gold layer, all of which are coupled with
each other. The titanium or tantalum layer is sandwiched between the
copper stud and a nickel-iron alloy layer, while the nickel-iron alloy
layer is sandwiched between the titanium or tantalum layer and the gold
layer which is exposed to be bonded with the solder.

[0047]FIG. 8 illustrates a slider 310 of a second embodiment according to
the present invention. Referring to FIG. 8, as the same with the first
embodiment, the slider 310 includes a trailing surface 311, a mounting
surface and an air bearing surface 312 opposite to the mounting surface.
Wherein the mounting surface is bonded with a suspension tongue by epoxy
or other adhesive materials. The slider 310 further includes five first
connection pads 313 and five second connection pads 314. Each of the
first connection pads 313 includes a bonding portion 313a for bonding and
a testing portion 313b electrically connected to the bonding portion 313a
for testing. All the bonding portions 313a and the second connection pads
314 are arranged in a row while all the testing portions 313b are
arranged in another row. The main distinction between the second
embodiment and the first embodiment is that the bonding portions 313a and
the second connection pads 314 are not disposed alternately. The five
bonding portions 313a are adjacent to each other. The five second
connection pads 314 are also adjacent to each other.

[0048]FIG. 9 illustrates a slider 410 of a third embodiment according to
the present invention. Referring to FIG. 9, the main distinction between
the third embodiment and the first embodiment is that the slider of the
third embodiment includes ten first connection pads 413 but no second
connection pad. Each first connection pads 413 includes a bonding portion
413a for bonding and a testing portion 413b electrically connected to the
bonding portion 413a for testing. The ten bonding portions 413a are
arranged to be a first row adjacent to the mounting surface of the slider
410. While the ten testing portions 413b are arranged in two rows, each
of which has five testing portions 413b.

[0049] It should be noted that the slider 210 may be replaced by any one
of the slider 310 and 410 which are described in the embodiment motioned
above. It also should be noted that the connection pads are not limited
to be ten but can be varied according to actual requirement.

[0050]FIG. 10 is a disk drive unit 1000 according to an embodiment of the
invention. The disk drive unit 1000 includes the HGA 200, a drive arm 300
connected to the HGA 200, a series of rotatable disks 400, and a spindle
motor 500 to spin the disk 400, all of which are mounted in a housing
600. Because the structure and/or assembly process of disk drive unit of
the present invention are well known to persons ordinarily skilled in the
art, a detailed description of such structure and assembly is omitted
herefrom.

[0051] While the invention has been described in connection with what are
presently considered to be the most practical and preferred embodiments,
it is to be understood that the invention is not to be limited to the
disclosed embodiments, but on the contrary, is intended to cover various
modifications and equivalent arrangements included within the spirit and
scope of the invention.